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As part of the Minnesota Children's Pesticide Exposure Study we measured volatile organic compound (VOC) concentrations in a probability sample of households with children. The 6-day average concentrations for 10 common VOCs were obtained in urban and nonurban residences twice during this multiphase study: screening-phase indoor measurements were collected in 284 households, and in the intensive-phase matched outdoor (O), indoor (I), and personal (P) measurements were collected in a subset (N=72) of the screened households. Screening-phase households with smokers had significantly higher concentrations of benzene and styrene compared to nonsmoking households; households with an attached garage had significantly higher levels of benzene, chloroform, styrene, and m/p- and o-xylene compared to households without an attached garage; and nonurban residences, which had a greater prevalence of smokers and attached garages, had significantly higher 1,1,1-trichloroethane, styrene, and toluene and significantly lower tetrachloroethylene concentrations compared to urban households. The screening-phase weighted distributions estimate the mean and variability in indoor VOC concentrations for more than 45,000 households with children in the census tracts sampled. Overall, median indoor concentrations of most VOCs measured in this study were similar to or lower than indoor levels measured previously in the United States. Intensive-phase outdoor VOC concentrations were generally lower than other major metropolitan areas, but urban concentrations were significantly higher than nonurban concentrations for all compounds except 1,1,1-trichloroethylene. A consistent pattern of P>I>O was observed for nine of 10 VOCs, with 1,1,1-trichloroethylene (I>P>O) being the only exception to this pattern. For most children, the indoor at-home microevironment was strongly associated with personal exposure after controlling for important covariates, but the ratio of median to upper bound exposures was smaller than that observed in studies of adults. There are relatively little data on VOC exposures in children, so these results are useful for estimating the central tendency and distribution of VOC exposures in locations where children spend a majority of their time.

Background: During the design phase of a clinical trial, sample size estimates should take into account medical screening criteria, the 'healthy volunteer' effect, consequences of run-in phases, and secular trends in the event rate of interest. All of these have been shown to relate to subsequent event rates, and hence trial power to detect intervention effects. The Multiple Risk Factor Intervention Trial (MRFIT) used three successive screenings of 361 662 men to enroll 12 866; observed coronary heart disease (CHD) mortality after a mean of 6.9 years was substantially lower than projected during design. We explore factors which may have contributed to these mortality differences and whether they persisted throughout follow-up., Methods: Proportional hazards models were used to compare 25-year mortality according to trial eligibility, self-exclusions, medical exclusions, and participation., Results: After adjustment for baseline risk factors and age, there was higher mortality among men excluded for presence of disease [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.43-1.61, for total; HR 1.92, CI 1.75-2.11, for CHD] compared to those not excluded which persisted throughout follow-up. Volunteers had lower total (HR 0.82, CI 0.76-0.87) and CHD (HR 0.79, CI 0.70-0.88) mortality than those discontinuing participation. Men excluded with characteristics deemed likely to interfere with adherence had higher total (HR 1.19, CI 1.07-1.33) and non-cardiovascular disease (CVD) (HR 1.32, CI 1.14-1.53) mortality but no higher CVD (HR 1.04, CI 0.88-1.23) or CHD (HR 0.98, CI 0.80-1.20) mortality compared to those not excluded. Differences in mortality were stronger during the first five years, but declined only slightly over 25 years., Conclusions: 25-year mortality was significantly higher for non-volunteers and exclusions. Differences between observed and predicted six-year total mortality for trial participants were largely attributable to volunteers and exclusions, but there were additional differences for CHD mortality, which were likely due to downward secular trends. These results emphasize the importance of anticipating these factors during clinical trial design, even for trials of short duration.

Background: Patients who report use of herbs to their physicians may not be able to accurately describe the ingredients or recommended dosage because the products for the same herb may differ. The purpose of this study was to describe variations in label information of products for each of the 10 most commonly purchased herbs., Methods: Products for each of 10 herbs were surveyed in a convenience sample of 20 retail stores in a large metropolitan area. Herbs were those with the greatest sales dollars in 1998: echinacea, St John's wort, Ginkgo biloba, garlic, saw palmetto, ginseng, goldenseal, aloe, Siberian ginseng, and valerian., Results: Each herb had a large range in label ingredients and recommended daily dose (RDD) across available products. Strengths were not directly comparable because of ingredient variability. Among 880 products, 43% were consistent with a benchmark in ingredients and RDD, 20% in ingredients only, and 37% were either not consistent or label information was insufficient. Price per RDD was a significant predictor of consistency with the benchmark, but store type was not., Conclusions: Persons self-medicating with an herb may be ingesting ingredients substantially different from that recommended by a benchmark, both in quantity and content. Higher price per label RDD was the best predictor of consistency with a benchmark. This study demonstrates that health providers and consumers need to closely examine label ingredients of presumably the same or similar herbal products.

Background: Forced expiratory volume in 1 second (FEV(1)) may be useful for identifying smokers at higher risk of lung cancer. We examined the association of FEV(1) with lung cancer mortality (LCM) among cigarette smokers in the Multiple Risk Factor Intervention Trial (MRFIT)., Methods: In all, 6613 MRFIT baseline smokers alive at trial end in 1982 had acceptable FEV(1) measures and complete smoking history; men were classified as during-trial long-term quitters (N = 1292), intermittent quitters (1961), and never quitters (3360). Proportional hazards models for LCM were fit with quintiles of average FEV(1), adjusted for age, height, race, smoking history, and other risk factors., Results: For long-term, intermittent, and never quitters respectively, mean baseline cigarettes/ day was 28, 32, and 35; trial-averaged FEV(1) was 3201, 3146, and 3082 ml; and average decline in FEV(1) was -46.0, -54.6, and -62.5 ml/year. With median post-trial mortality follow-up of 18 years, there were 363 lung cancer deaths. Age-adjusted LCM rates varied across FEV(1) quintiles from 50 (lowest quintile) to 11 (highest quintile), 58 to 11, and 76 to 20, per 10 000 person-years, for long-term quitters, intermittent quitters, and never quitters, respectively. Multivariate adjusted hazard ratios for 100 ml higher FEV(1) were 0.92 [P = 0.004], 0.95 [P = 0.003], and 0.95 [P < 0.0001] respectively., Conclusions: These results demonstrate the strong predictive value of FEV(1) for lung cancer among cigarette smokers independent of smoking history; results did not differ by during-trial quit status. FEV(1) may be a biological marker for smoking dose or it may be that genetic susceptibilities to both decreased FEV(1) and lung cancer are associated.

Although 1 of 10 nursing home residents is taking an antiepileptic drug (AED), no study to our knowledge has determined whether most residents are already receiving AED treatment when they are admitted or are given these drugs afterward. That differentiation was the focus of this study. The study group consisted of 10,318 residents, 65 years and older, admitted to 510 nursing homes located throughout the United States during the first quarter of 1999. AED prevalence at admission was 7.7%; three fifths had an epilepsy/seizure indication. In a multivariate analysis, factors associated with AED use at admission included epilepsy/seizure, bipolar depression, age group, and cognitive performance. In the follow-up cohort (N = 9,516), postadmission initiation of AEDs was 2.7%; one fifth had an epilepsy/seizure indication. In the multivariate analysis, factors associated with postadmission AED initiation included epilepsy/seizure indication, bipolar depression, age group, peripheral vascular disease, and cognitive performance. This rate of AED postadmission initiation within the first 3 months of admission was much higher than expected, suggesting that new symptoms may develop after admission. Results also show that the rate of AED use in nursing homes is not static.

Background: It remains unclear whether hypertriglyceridemia is an independent risk factor for coronary heart disease (CHD), and whether fasting and nonfasting triglyceride (TG) levels are equally predictive., Methods: A total of 2809 (of 12 866) men randomized during 1973 through 1975 into the Multiple Risk Factor Intervention Trial with fasting and nonfasting TG levels measured at baseline were followed up for CHD incidence and death. Proportional hazards regression models were used to assess associations of fasting and nonfasting TG levels with CHD., Results: Average fasting and nonfasting TG levels were 187 and 284 mg/dL (2.11 and 3.21 mmol/L), respectively. Prevalence of hypertriglyceridemia (200 mg/dL [2.26 mmol/L] or more) was 31% for fasting and 61% for nonfasting. There were 175 nonfatal or fatal CHD events during 8 years and 328 CHD deaths during 25 years. Compared with TG levels less than 200 mg/dL, risk factor-adjusted hazard ratios for CHD mortality for hypertriglyceridemia were 1.24 (P =.09) for fasting and 1.26 (P =.07) for nonfasting. For nonfatal or fatal CHD, fasting and nonfasting TG levels were similarly predictive with hazard ratios of 1.64 (P =.004) for fasting and 1.46 (P =.03) for nonfasting. These associations for fasting TG levels were assessed to be underestimated by 56% because of regression dilution bias, with attenuation likely greater for nonfasting TG levels., Conclusions: Greater ease of obtaining nonfasting than fasting measurements, greater prevalence of hypertriglyceridemia with nonfasting than fasting values, and similarly increased risk with each indicate that nonfasting TG levels may be more useful than fasting ones for risk stratification.

Objective: To report long-term risks for total, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality associated with incident diabetes (using current diagnostic criteria) and with incident nonfatal CVD (NF-CVD)., Research Design and Methods: A total of 11645 participants without diabetes or CVD at baseline from the Multiple Risk Factor Intervention Trial who survived to the end of the trial were grouped by during-trial incident diabetes and/or NF-CVD events: neither diabetes nor NF-CVD, diabetes only, NF-CVD only, or both diabetes and NF-CVD. Incident diabetes was defined by use of hypoglycemic agents or fasting glucose >or=126 mg/dl at any time over the 6 trial years. Proportional hazards models tested group differences in mortality over 18 post-trial years., Results: Among 3859 total deaths were 1846 from CVD and 1277 from CHD, with death rates per 10000 person-years of 203, 97, and 67, respectively. Multivariate-adjusted hazard ratios (HRs) for total mortality were 2.75 (P < 0.0001) for those with NF-CVD and diabetes both, 1.92 (P < 0.0001) for those with NF-CVD only, and 1.49 (P < 0.0001) for those with diabetes only, relative to neither diabetes nor NF-CVD. NF-CVD was associated with a higher hazard of death than diabetes for total (HR 1.29, P = 0.0004), CVD (HR 1.76, P < 0.0001), and CHD (HR 1.88, P < 0.0001) mortality. Only the subgroup of participants on hypoglycemic agents showed an equivalent risk of total mortality relative to participants with NF-CVD (HR 0.93, P = 0.54)., Conclusions: Current diabetes diagnostic criteria conferred significantly increased total, CVD, and CHD mortality risks independent of the impact of NF-CVD. NF-CVD was more strongly predictive of mortality.

The ability of questionnaires to predict children's exposure to pesticides was examined as part of the Minnesota Children's Pesticide Exposure Study (MNCPES). The MNCPES focused on a probability sample of 102 children between the ages of 3 and 13 years living in either urban (Minneapolis and St. Paul, MN) or nonurban (Rice and Goodhue Counties in Minnesota) households. Samples were collected in a variety of relevant media (air, food, beverages, tap water, house dust, soil, urine), and chemical analyses emphasized three organophosphate insecticides (chlorpyrifos, diazinon, malathion) and a herbicide (atrazine). Results indicate that the residential pesticide-use questions and overall screening approach used in the MNCPES were ineffective for identifying and oversampling children/households with higher levels of individual target pesticides.